U.S. patent application number 13/723000 was filed with the patent office on 2013-05-02 for butt-mounted shaft extension for a golf club.
This patent application is currently assigned to ACUSHNET COMPANY. The applicant listed for this patent is Acushnet Company. Invention is credited to Bradford Hughes Hartwell, Kenneth C. Scott, Peter L. Soracco.
Application Number | 20130109492 13/723000 |
Document ID | / |
Family ID | 44788595 |
Filed Date | 2013-05-02 |
United States Patent
Application |
20130109492 |
Kind Code |
A1 |
Soracco; Peter L. ; et
al. |
May 2, 2013 |
BUTT-MOUNTED SHAFT EXTENSION FOR A GOLF CLUB
Abstract
A device designed for extending a golf club shaft. The device is
a three-piece mechanism with a bottom piece bonded into the top end
of a tubular golf club shaft, and a plurality of top piece sizes
that are connected to the bottom piece and provide a plurality of
club lengths. A special golf grip having an accordion like
plurality of rings can expand or contract in accordance with the
amount of club length adjustment.
Inventors: |
Soracco; Peter L.;
(Carlsbad, CA) ; Hartwell; Bradford Hughes;
(Encinitas, CA) ; Scott; Kenneth C.; (San Marcos,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Acushnet Company; |
Fairhaven |
MA |
US |
|
|
Assignee: |
ACUSHNET COMPANY
Fairhaven
MA
|
Family ID: |
44788595 |
Appl. No.: |
13/723000 |
Filed: |
December 20, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12760884 |
Apr 15, 2010 |
8348783 |
|
|
13723000 |
|
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Current U.S.
Class: |
473/296 |
Current CPC
Class: |
A63B 53/14 20130101;
A63B 60/28 20151001; A63B 53/12 20130101; A63B 60/16 20151001; A63B
60/22 20151001; A63B 53/10 20130101 |
Class at
Publication: |
473/296 |
International
Class: |
A63B 53/16 20060101
A63B053/16 |
Claims
1. An extension device for a golf club shaft, comprising: a top
piece, a bottom piece, an inner screw, and a grip to cover the
device; the bottom piece fitted into a tubular opening of the golf
club shaft; the top piece having a cylindrical opening traversing
along its axis and a plurality of teeth extending from a lower
surface; the bottom piece having a threaded center section and a
plurality of receptacles corresponding in dimension and location to
the teeth, wherein the top and bottom pieces can be pressed
together; and the inner screw traversing through the top piece and
having a threaded lower end which engages a treaded section of the
bottom piece, wherein a golfer by using an appropriate tool can by
turning the inner screw tightened the top piece into the bottom
piece.
2. The extension device of claim 1, wherein the bottom piece is
bonded into the golf club shaft by glue or epoxy.
3. The extension device according to claim 1, wherein the grip
comprises a series of pleated rings that expand or contract in
compliance with length adjustments of the shaft.
4. The extension device according to claim 1, wherein the grip has
an opening in the butt-end of the grip to allow access of a tool to
rotate the inner screw.
5. The extension device according to claim 1, wherein the number of
teeth and receptacles is three.
6. The extension device according to claim 1, wherein the top piece
being available in varying lengths to provide varying shaft
lengths.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of co-pending U.S. patent
application Ser. No. 12/760,884, filed on Apr. 15, 2010, which is
incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to a device for
adjusting the length of a golf shaft. In particular, the invention
concerns extending the length of the shaft by utilizing the device
at the gripping end of the club.
BACKGROUND OF THE INVENTION
[0003] One of the most important factors in golf club equipment is
the club shaft. The shaft transfers the golfer's power to the club.
It provides the length, the flex, the torque and the weight for the
club, therein giving the swing plane and shot desired.
[0004] Golf club shafts are available in various types of materials
and structures. Steel shafts are stronger, last longer, more
durable and generally less expensive than graphite or carbon fiber
shafts, and are usually made from carbon steel, although stainless
steel is sometimes used. The steel shafts are available in stepped
or rifle designs. The graphite shafts are more expensive and less
durable; however, the lighter weight creates greater swing speed
for more power. Also available are multi-material and titanium
shafts.
[0005] When installing a shaft, the proper length must be
accurately determined. The length is as important to a golf shaft
as is the flex or torque. Most measurements of shaft length involve
a determination of a particular player's height and distance of his
hands to the floor. Shaft length will impact whereon the clubface
the ball will be consistently struck, and often, an incorrect shaft
length is the main cause of a golfer to alter his natural swing arc
in order to make optimum impact. According to most research, if
ball impact is but 1 inch off-centre this can equate to a 14% loss
of carry distance, so it is vitally important that the length of
the club be accurately fitted for each particular player.
[0006] If it is seen in the fitting process that a player needs to
adjust his club, such as adding an inch or two to the length of the
club, it would be highly desirable to lengthen his present club(s)
rather buy and install new shafts.
[0007] Prior art shafts having adjustable lengths have been used
for many years for a wide variety of applications. Each of these
applications has its own functional and aesthetic requirements for
the shaft construction which is employed. As a consequence, a
number of different mechanisms and devices have been developed to
satisfy the particular application requirements. A majority of golf
club shaft extension patents are directed to use mainly as putters,
or to extending shafts of an existing set of clubs to accommodate
growing children. While the teachings of the present invention may
be adapted to these types of applications, the focus is rather to
make a club adjustment that is rigid, secure, and easily
fastened.
SUMMARY OF THE INVENTION
[0008] The present invention provides for an extension device for
use on the butt-end of a golf club shaft. The device consists of
three basic parts: a top piece; a bottom piece; and an inner screw.
The bottom piece is bonded, by glue or epoxy, into the tubular
opening in the top of the club shaft. The top piece is attached to
the bottom and provides for an extension in the club length. The
invention can be used to extend any of the golf clubs in a set, but
preferably is designed for use with a driver. Holding the device
together in a tight unitary structure is an inner screw that
traverses through the pieces.
[0009] In one embodiment of the invention the bottom piece has a
plurality of resilient legs that are inserted and bonding into the
upper end of the shaft. The top piece is attached in a removable
sliding relationship to the bottom piece and by rotation of the
inner screw; the device can extend and contract. The greatest
variation in shaft length is basically achieved by having multiple
top pieces that vary in length, however, minor adjustments in
length can be achieved by rotation of the inner screw, therein
causing the top piece to either expand or contract from the bottom
piece. Once the device is installed it is covered by a grip. The
invention requires the use of a special grip that has an opening in
the butt-end for access of a tool wielded by the golfer, whereby by
turning the inner screw the golfer can make small but important
refinements in club length. The grip includes a series of pleated
rings that can expand or contract like an accordion in response to
changes in length of the device.
[0010] Another embodiment of the invention attaches the top piece
into a bottom piece by essentially snapping the pieces together and
then tightening the device with a screw traversing through the
pieces. The length extensions of the shaft being achieved by the
selection of interchangeable top pieces of varying lengths.
[0011] Another embodiment of the invention forms the device by
screwing the top piece into the bottom piece and tightening the
device with an inner screw.
[0012] Other advantages of the invention will be more fully
apparent from the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a view of two club shaft butt-ends, one
illustrating the club when in the standard position and the other
when the club shaft has been extended.
[0014] FIG. 2 is a pictorial view of the extension mechanism when
in a complete state.
[0015] FIG. 3 is a symmetrical lengthwise view of the top piece of
the butt extension.
[0016] FIG. 4 is a cross sectional view of FIG. 3 with the turning
screw installed.
[0017] FIG. 5 is a symmetrical view of the bottom piece of the butt
extension.
[0018] FIG. 6 is a cross-sectional view of FIG. 5 with the turning
screw installed.
[0019] FIG. 7 is a cross-sectional view of the mechanism bonded to
top of club shaft.
[0020] FIG. 8 is a symmetrical view of the shaft with length
extended.
[0021] FIG. 9 is a cross-sectional view of the grip covering the
mechanism.
[0022] FIG. 10 is a perspective view of another embodiment of the
invention.
[0023] FIG. 11 is an expanded bottom perspective view of the
embodiment of FIG. 10.
[0024] FIG. 12 is a perspective view of the upper portion of FIG.
10.
[0025] FIG. 13 is a top perspective view of the lower portion of
FIG. 10.
[0026] FIG. 14 is a detailed prospective view of another embodiment
of the invention.
[0027] FIG. 15 is an expanded view of the device shown in FIG.
14.
[0028] FIG. 16 is a perspective view of the upper portion of the
device of FIG. 14.
[0029] FIG. 17 is a perspective view of the lower portion of the
device of FIG. 14.
DETAILED DESCRIPTION OF THE INVENTION
[0030] FIG. 1 shows the comparison in the grip end between a
standard club 100 and a club 102 that has been adjusted by the
extension device of the present invention. The amount of the
extension E is typically between 0.125 to 3 inches.
[0031] FIG. 2 is an illustration of the generic device 104 of the
present invention. It is comprised of three basic pieces, a top
piece 106, a bottom piece 108, and an inner screw 110 that holds
the device securely together.
[0032] FIGS. 3 and 4 describe the top piece 106 of this invention
which consists of a longitudinal cylindrical sidewall containing a
plurality of slots 112 defined therein. The slots 112 are molded
into the top piece 106 and preferably there are three. The upper
end 114 of the top piece 106 contains an upper recess 126 for
seating of the top end 118 of the inner screw 110. The lower end
116 has a lower recess 124 defined therein and between the recesses
124, 126 is a clearance hole along the axis of the top piece 106
for free passage of the inner screw 110. As seen in FIG. 4, these
recesses 124, 126, provide room to securely hold the inner screw
110 which has a conventional type of fitting and is capable of
being turned by a conventional tool. The inner screw 110 contains
first and second locking nuts 120, 122 essential to the operation
of the device as described below. The bottom end of the screw 110,
although not shown in FIG. 4 is threaded on the lower portion.
[0033] FIGS. 5-8 describe the bottom piece 108 which comprises a
plurality of fingers 130 which extend upwardly and have distal ends
132. The fingers are preferably three in number and are shaped and
sized to coordinately slide into and within the slots 112 of the
top piece 106. The lower section of the bottom piece 108 has a
plurality of resilient legs 134 which have distal ends 136 that are
pressed with great bias into the open top end of the golf shaft,
this is best shown on FIGS. 7-9.
[0034] FIGS. 6-9 show the second locking nut 122 of the inner screw
110 movably disposed in the chamber 138 of the bottom piece 108, as
it is free to traverse within the chamber 138 when actuated by the
turning of the screw 110. FIGS. 7-8 illustrate the entire device
102 with the bottom piece 108 bonded, by glue or epoxy, to the
inner wall of the golf club shaft 140. In a standard position,
shown in FIG. 7, the fingers 130 of the bottom piece 108 come to an
abutment with the slots 112 of the top piece 106. At that point any
lengthening of the shaft is due entirely to the length of the
device extending from the top of the shaft. FIG. 8 is illustrative
of what results when the device has been actuated by turning the
screw 110 and the first and second locking nuts 120, 122 come into
engagement with the top piece 106 therein lifting the top piece
away from the bottom piece 108. The amount of this extension
tweaking can be indicated by the distance of the gaps 142 that
appear in FIG. 8. The length of the adjustment is controlled by the
second locking nut 122 coming to rest against the stop 128. While
not shown, the chamber 138 is threaded to allow a controlled,
precise movement therein. The gaps 142 are not of a size that would
be perceivable to the golfer through the grip 112.
[0035] FIG. 9 is a cross-sectional view of the entire device 104
installed in the tubular shaft 140 with the grip 144 having pleated
rings 146. Since the device 104 may vary in length, it is necessary
that the grip is capable of adjusting to various shaft lengths. The
grip shown in FIG. 9 has pleated rings that operate like an
accordion when the grip stretches or contracts to accommodate the
various extensions of the device. The grip 144 has a top opening
for access of the tool to adjust the length or remove the top
piece.
[0036] Another embodiment of the invention is shown on FIGS. 10-13,
wherein a device 204 has basic three pieces, the top piece 206, the
bottom piece 208 and the inner screw 210. This embodiment 204
presses the bottom piece 208 into the upper shaft 140 of the golf
club and connects the top and bottom pieces by snap-fitting a
plurality of teeth 212 located on the lower surface 216 of the top
piece 206 into a like number of receptacles 222 defined in the
upper surface 220 of the bottom piece 208. The preferred number of
teeth 212 and receptacles 222 being three. With this embodiment,
varying the extension length is a direct function of the varying
lengths of the top piece 206. The device 204 is tightened by an
inner screw 210 which is located at the upper surface 218 of the
top piece 206 and traverses the top piece through a cylindrical
opening 214 and then screws into a threaded section 224 of the
bottom piece 208. In actual operation, the user rotates the screw
210 by using a standard tool that fits in an opening at the top of
the grip. To adjust the length the golfer removes the screw 210 and
unsnaps the top piece 206 from the bottom piece 208 and replaces it
with a top piece of another size length, either shorter or longer,
therein causing the change to the overall the club length.
[0037] Another embodiment of the invention is shown in FIGS. 14-17,
wherein the top piece 306 is screwed into the bottom piece 308 and
the inner screw 310 tightens and secures the device 304. The top
piece 306 has a longitudinal cylindrical opening 318 that runs
through the piece which has two major segments: a cylindrically
shaped upper body 312 and a large threaded segment 314 for screwing
into the bottom piece 308. The bottom piece has a large threaded
receptacle 316 in the top surface 322 of the bottom piece 308 for
accepting the large threaded segment 314 of the top piece and a
smaller threaded opening 320 for accepting the threaded bottom
section of the inner screw 310. To adjust the length of the shaft,
the golfer removes the screw 310 and unscrews the top piece 306
from the bottom piece 308 and as above replaces it with a top piece
of another length, either shorter or longer, therein creating the
desired overall the club length.
[0038] Conformance with the rules of golf and acceptance by the
USGA is an important consideration in this invention. As discussed
above, the features of lengthening the club shaft must be such that
it is virtually impossible to assemble and use in a manner which is
not conforming. An aspect of this conformance is that any club with
adjustable parts must have its parts firmly fixed with no
reasonable likelihood of them working loose during a round of golf.
The use of the inner screw and structure of the top and bottom
pieces assures such protection.
[0039] It will be understood that various modifications to the
preferred embodiment disclosed above may be made. The above
description is not intended to limit the meaning of the words used
in the following claims that define the invention. Rather, it is
contemplated that future modifications in structure, function or
result will exist that are not substantial changes and that all
such insubstantial changes are intended to be covered by the
following claims.
* * * * *